1. Field of the Invention
The invention relates to a wing structure for aircraft. More particularly, the invention relates to an apparatus, and method for its use, of a folding wing structure for a very high altitude aircraft. This particular invention combines both inflatable and rigid hinged elements.
2. Background Art
For aircraft that operate at very high altitudes, the wing structure is a very important criterion. Very high altitudes means altitudes between about 85,000 feet and about 150,000 feet above sea level (ASL). At these altitudes, air densities are very low, and therefore generally, wing structures need to be relatively large areas compared to a similarly sized aircraft operating at lower altitudes of, for example, about 35,000 to 45,000 feet ASL, in order to generate the lift necessary to functionally fly.
Furthermore, if an aircraft is developed to operate at such altitudes, it is desirable to allot as much weight as possible to payload (e.g., sensors, and things of that nature), and to minimize unnecessary weight expenditures wherever possible. As a result, the use of composite materials has recently increased. If the wings could be made of composite and/or inflatable materials, yet still provide the wing area and lift necessary to properly operate at the desired high altitudes, an enormous operating benefit can be obtained.
Because of recent historical developments, a need has been developed to place unmanned aerial vehicles to locations literally around the ground within several hours notice. One manner of deployment can be via rockets, launched from ground locations and/or ocean-going ships. In these cases, the aircraft would have to be foldable and be able to quickly begin operating at high altitudes upon deployment from the rocket.
Thus, a need exists to develop a foldable aircraft, with foldable inflatable wings that can operate at very high altitudes.